A silicon substrate has a protective film formed on each side. A semiconductor surface opening not smaller than a given region is formed by removing the protective film. A through-hole having an inner size smaller than the given region is formed in the opening by laser machining. Thereafter, the inner size of the through-hole is increased by anisotropic etching, and the etching is ended when the inner size of the through-hole reaches the given size. In this way, a through-hole of a given size can be formed without allowing reversely tapered crystal planes to appear from a surface of the substrate toward the inside of the through-hole.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A semiconductor device with a through-hole electrically connecting a front surface and a rear surface, comprising: a semiconductor substrate having a surface of a { 100 } crystal plane orientation; a protective film formed on the surface of the semiconductor substrate, the protective film having an opening where the semiconductor substrate is partially exposed; and a through-hole formed inside the opening to have an inner size smaller than that of the opening, wherein the through-hole has a tapered shape in a direction where its inner size becomes smaller near the opening, wherein an insulating layer is formed on an inner surface of the through-hole and a conductive layer is formed on an inner surface of the insulating layer, and wherein the conductive layer electrically connects the front surface and rear surface of the semiconductor substrate.
2. A semiconductor device according to claim 1 , wherein the inner size of the through-hole is nearly equal to that of the protective-film-removed portion, and wherein the through-hole is perpendicular to the semiconductor substrate.
3. A semiconductor device according to claim 1 , wherein a profile of the through-hole and a profile of the opening are each rectangular and intersect each other at right angles, and wherein a length of a diagonal line of a horizontal section of the through-hole becomes nearly equal to a length of a side of a region on which the protective film is removed.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 23, 2005
October 9, 2007
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